Yesterday, officials showed up in uniform and began painting our neighborhood tree trunks white. They coated every tree—why?

What Type of Paint Is Used?
People do not use standard wall paint, which can suffocate the bark.
Instead, the mixture is typically:

A diluted white latex paint
1 part white latex paint
1 part water
Or a traditional whitewash mixture of:

Hydrated lime
Water
A small amount of salt
This creates a breathable coating that won’t harm the tree.

Why Only the Bottom Half?
Because this is the part most vulnerable to:

Sun heat during winter
Rodent attacks
Insects climbing
Fungus and moisture exposure
Mechanical damage (like lawn equipment)
There’s no need to paint the entire trunk.